To better implement services and understand the scope of autism spectrum disorders (ASDs), researchers and service providers need an accurate count of how many people are affected by ASDs. Since 2000 Drs. Charles and Nicholas, funded by the Centers for Disease Control and Prevention, have been monitoring rates of ASDs in 8-year-olds in South Carolina. Their research has found that as many as 84 percent of children with ASDs showed some sign of developmental delay before age three. This study would allow the researchers to expand their surveillance of ASDs in South Carolina by also looking at rates of ASDs in four-year-olds. The research team evaluates the rate of ASDs through a thorough examination of medical, school and public health records, including records from major medical centers and the South Carolina Department of Health and Environmental Control (DHEC). This grant will allow them to expand their data sources to include those relevant to young children. In particular, they will examine records from the Medical University of South Carolina, which provides assessment and treatment services to children with developmental disabilities beginning at birth. The investigators also have access to data from a program administered by DHEC called Babynet, which provides services for children zero to three. What this means for people with autism: This project will provide important information about the number of young children with ASDs as well as how well service providers are executing early detection. This information can be used for planning and implementation of ASD-related services.